1. Field of the Invention
The present invention relates to a method of manufacturing an electronic parts packaging structure and, more particularly, a method of manufacturing an electronic parts packaging structure having such a structure that an electronic parts is embedded in an insulating layer.
2. Description of the Related Art
In the prior art, there is the electronic parts packaging structure having such a structure that the electronic parts is embedded in the insulating layer. As an example of the method of manufacturing such electronic parts packaging structure, as shown in a lower view of FIG. 1A, first bumps 202 of an electronic parts 200 are flip-chip bonded onto a lower copper foil 100, and then an underfill resin 102 is filled in a clearance between the electronic parts 200 and the lower copper foil 100.
Then, as shown in middle and upper views of FIG. 1A, an uncured resin film 106, in which conductive posts 104 are provided, and an upper copper foil 110 are arranged over the electronic parts 200, and then these elements are pushed against the electronic parts 200 side. Consequently, as shown in FIG. 1B, the electronic parts 200 is embedded in a resin film 106a and also the upper copper foil 110 is adhered onto the resin film 106a. At this time, the conductive post 104 is connected electrically to the lower copper foil 100 and the upper copper foil 110 respectively.
Then, the interlayer insulating layer 106, in which the electronic parts 200 is embedded, is obtained by curing the uncured resin film 106a by means of the annealing. Then, as shown in FIG. 1C, wiring patterns 108 that are connected mutually via the conductive post 104 are formed on both surface sides of the interlayer insulating layer 106 respectively by patterning the upper copper foil 110 and the lower copper foil 100. Then, a predetermined built-up wiring connected to the wiring patterns 108 is stacked, as the case may be.
The method similar to such manufacturing method is set forth in Patent Literature 1 (Patent Application Publication (KOKAI) 2002-261449), for example.
However, the underfill resin 102 formed of the different material from the interlayer insulating layer 106 is present under the electronic parts 200. Thus, when the reliability test using the thermal cycle is executed, the thermal stress is generated due to the difference of coefficients of the thermal expansion between these elements. Therefore, there exists the problem that either the crack is caused in the interlayer insulating layer 106 or the contact failure is generated between the electronic parts 200 and the wiring patterns 108. Also, when the electronic parts is face-up mounted, the back side of the electronic parts must be bonded onto the substrate via the die attaching material the material of which is different from the interlayer insulating layer. As a result, the similar problem is ready to occur.
In addition, the method of embedding the electronic parts in the resin film by pushing the electronic parts against the uncured resin film may be employed. According to this method, the uncured resin film 106a can have flexibility to some extent, nevertheless in some cases the fault such as the crack, or the like may be caused in the electronic parts whose mechanical strength is weak because the electronic parts must be pushed by applying a relatively high pressure.